Which types of orbitals are found in the principal energy level n = 3?
a. s, d

b. s, p, d

c. s, p

d. s, p, f

e. s, d, f

The principal energy level at n=3 contains s,p,d orbitals in their valence shell.

Option(b);

Explanation:

"Principal energy level" is used to locate the no of electrons in each orbital to its atomic nucleus. These energy levels are denoted by the "principal quantum number" n.

There are four energy level of orbits available in this system. And the following shows different level of orbits and the no of electrons for each value of n

At n=1, Orbital name=S, No of electrons=1At n=2, Orbital name=S, P, No of electrons=4At n=3, Orbital name=S, P, D, No of electrons=9At n=4, Orbital name=S, P, D, F, No of electrons=16

North atlantic current or north atlantic drift is the answer

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic